Norrona Trollveggen Heavy Duty Merino durable socks are made for demanding alpine climbing but work perfectly for all-season mountaineering adventures and general outdoor activities. Norrona Trollveggen Heavy Duty Merino durable socks are made for demanding alpine climbing but work perfectly for all-season mountaineering adventures and general outdoor activities. The fabric is made of 55% Merino Wool, 33% nylon , 13% multifilament nylon, 1% elastane mix. The premium Merino Wool is temperature-regulating, retains body heat while transporting moisture away effectively keeping you warm, even when wet, and is also natural odor-resistant. The nylon improves durability at a low weight and has moisture-wicking and quick-drying properties. The sock has a mid high cut for use in mountain boots.